Fluid streams such as liquid flows and gaseous flows (e.g. air flows) often carry particulates that are often undesirable contaminants entrained in the fluid stream. Filters are commonly employed to remove some or all of the particulates from the fluid stream.
Filter media including fine fibers formed using an electrostatic spinning process is also known. Such prior art includes Filter Material Construction and Method, U.S. Pat. No. 5,672,399; Cellulosic/Polyamide Composite, U.S. Patent Publication No. 2007/0163217; Filtration Medias, Fine Fibers Under 100 Nanometers, And Methods, U.S. Provisional Patent Application No. 60/989,218; Integrated Nanofiber Filter Media, U.S. Provision Patent Application No. 61/047,459; Filter Media Having Bi-Component Nanofiber Layer, U.S. Provisional Patent No. 61,047,455, the entire disclosures of which are incorporated herein by reference thereto as nanofibers and methodologies according to the foregoing may be utilized in embodiments of the present invention.
Electrospun nanofiber medias provide an excellent filter efficiency; however, its filter life span is relatively short due to heavy particle loading facilitated by nano pore sizes of the electrospun nanofiber medias. The present invention is directed toward improvements over the state of art of filter medias incorporating electrospun nanofibers.